Conventionally, as a technique regarding an optical disc drive, a technique for producing a write strategy signal in a signal processing integrated circuit device (digital signal processor: DSP) to differentially transmit the same to a laser diode driver (LDD) has been disclosed (see Japanese Patent Application Laid-Open Publication No. 2007-141406 (Patent Document 1) and Japanese Patent Laid-Open Application Publication No. 2006-120252 (Patent Document 2), for example).